This invention relates to apparatus and methods of providing an actuated lid for a process chamber.
In many semiconductor-manufacturing processes, substrates are processed in a series of one or more phases. For example, substrates can undergo a pre-heating phase during which the substrate is heated to an initial temperature before the substrate is loaded completely into a processing chamber and processed with a prescribed heating cycle. To achieve the required device performance, yield, and process repeatability, the processing of a substrate such as a semiconductor wafer is strictly controlled inside a process chamber.
Generally, a process chamber has a chamber body enclosing components of the process chamber. The process chamber typically maintains vacuum and provides a sealed environment for process gases during substrate processing. On occasions, the process chamber needs to be periodically accessed to cleanse the chamber and to remove unwanted materials cumulating in the chamber. To support maintenance for the process chamber, an opening is typically provided at the top of the process chamber that is sufficiently large to provide access to the internal components of the process chamber.
To support these conflicting requirements, a lid is used to help the process chamber to provide a sealed environment for the processing gases during substrate processing by mating with the process chamber and incorporating an elastomeric seal between the lid and the process chamber, and to allow access to the inner chamber. Typically, a lid provides access to the components inside the chamber, and shields the operator from exposure to high temperatures during system operation. The lid generally remains closed during most process steps unless the chamber is opened, for example, to perform a preventive maintenance chamber cleaning, thereby breaking the vacuum and bringing the chamber to atmospheric pressure. Certain lids are manually dismounted and removed from the chamber before the chamber can be accessed. In other cases, lid hinges connect the lids to the chambers, and these hinges typically include locking ratchets to prevent the lids from unintentional collapses or closures that can slam the lids into the chambers with great force.
Originally, the lids were small and were easily handled by operators. As the chamber size increases to handle larger substrates, the lids increase in size. At present, lids have become relatively heavy, making opening and closing of the lids relatively difficult. Further, when closing a large, heavy lid, it is difficult to properly align the lid to obtain a proper seal.
In one aspect, a semiconductor processing system includes a chamber adapted to process a wafer, the chamber having an opening to facilitate access to the interior of the chamber. The system has a lid coupled to the chamber opening, the lid having an open position and a closed position. An actuator is connected to the lid to move the lid between the closed position and the open position. The system may optionally include a floating pivot coupled to the lid and the actuator to align the lid with the opening when the lid closes.
Implementations of the above aspect may include one or more of the following. A fixed pivot screw may be connected to the lid and the actuator. A guide link may be connected to the fixed pivot screw. A load link can be connected to the floating pivot screw. A guide shaft can be rotatably connected to the load link. The system also includes a drive pivot positioned at one end of the load link, and a rod extending from the actuator to the drive pivot can drive the lid. A support bracket can be provided to mount the actuator to the chamber body. The actuator can be air actuated or (hydraulically) actuated. Alternatively, the actuator can be motorized.
In another aspect, a floating pivot to automatically align a lid to a body of a semiconductor processing chamber includes a load link having first and second portions; a flanged bearing positioned between the first and second portions of the bearing; and a self-centering spring positioned around the perimeter of the bearing.
Implementations of the above aspect may include one or more of the following. The pivot can include a tension shim positioned between the load link and the bearing.
A pivot screw can be used to tighten the bearing. The self-centering spring can be an O-ring, leaf springs, coil springs, or any combinations thereof. A lid can be connected to a first end of the load link. A chamber body can be connected to a second end of the load link. The self-centering spring can be an elastomeric separator. The self-centering spring allows radial movements, axial movements, or both radial and axial movements. The self-centering spring also allows self-centering of the lid to the chamber body.
Advantages of the system may include one or more of the following. The system provides a removable lid that covers and seals an opening in the chamber when closed. The lid can also be selectively opened to provide access to the interior of the process chamber so that components inside the chamber may be removed for cleaning, repair or maintenance. When closed, the lid is properly aligned relative to the other processing components to facilitate repeatability and accuracy of the process.
The system supports a variety of instrumentation and devices on top of the lid while maintaining a small footprint by integrating more components onto the lid. The system operates even when the lid components cause the lid center of mass to be shifted or cantilevered behind the chamber without suffering from misalignment problems. Further, the lid with components mounted on top of the lid is easy to use, simple to assemble, reliable and inexpensive.
Other features and advantages will become apparent from the following description, including the drawings and the claims.